In recent years, attention is drawn to an optical function device on a silicon substrate for which a silicon electronic circuit fabrication technology capable of implementing large-scale integration at a low cost is utilized.
Meanwhile, in a high-performance server, a supercomputer and the like, enhancement of a performance is attempted by employment of a multicore configuration or the like for a CPU (Central Processing Unit) in order to satisfy a demand for enhancement of the computing power. On the other hand, in communication between chips or boards, communication by an electric signal is approaching a limit from a problem of a physical distance with respect to the computing power at an increasing speed.
An optical communication device on a large-scale silicon substrate based on a small-size silicon wire waveguide by low loss, namely, a silicon photonics, is expected as a technology that solves a problem of shortage of the communication capacity of an information processing apparatus whose speed is increasing as described above.
The silicon photonics is configured from silicon-based optical function elements such as an optical waveguide, a light emitting device, a light receiving device (photodetector), an optical modulator, an optical splitter and so forth.
It is expected that, for example, as an optical modulator in the silicon photonics, a ring optical modulator having a very small size, for example, of approximately several 10 μm2 to 100 μm2, and a low capacity is promising from the point of view of the power consumption and the high-speed response.